Fabricator Produces Parts Complete With VTC

Meeting customer demand for both quality components and consistent, on-time delivery is essential for any shop’s competitiveness. However, having to subcontract work that can’t be done in-house can add weeks or months to delivery times and compromise quality standards.

Case Study
From:
1/22/2008
Modern Machine Shop

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Equipped with a live spindle, the VTC is capable of drilling, tapping and milling operations.

Weldall specializes in large fabrications such as this 16-foot power generator awaiting shipment on a flatbed.

The live spindle is equipped with a right-angle head that eliminates the need for a second setup to machine features on the sides of parts.

The VTC has enabled Weldall to machine certain part features that would be impossible to mill. This contributes to the company’s ability to produce complete fabrications for its customers.

Meeting customer demand for both quality components and consistent, on-time delivery is essential for any shop’s competitiveness. However, having to subcontract work that can’t be done in-house can add weeks or months to delivery times and compromise quality standards. This was the issue faced by Weldall Manufacturing, a company specializing in medium- and large-sized fabrications. Driven by frustration over lack of control and mounting customer demand for complete fabrications, Weldall added CNC machining to its welding, plasma cutting and forming capabilities in 1993. The same factors recently drove the company to purchase its first vertical turning center, a Giddings & Lewis VTC 1600.

President David Bahl Sr. founded Weldall in 1973 in a small building with rented equipment while still working a full-time job. Today, the company operates out of a 144,000-square-foot facility and employs 130 people running two shifts. Mr. Bahl attributes the company’s steady growth to an emphasis on quality and customer service, a well-trained workforce and an ongoing commitment to stay abreast of the latest technologies. Along the way, Mr. Bahl’s sons, David Jr. and Dan, joined their father in the business.

Over the years, Weldall has produced some rather large fabrications, including the first tower crane for China’s Three Gorges Dam. The company can handle parts as heavy as 100,000 pounds. Its welding technology includes flux core, hard wire, gas metal arc and submerged arc. For automated welding, the company uses automatic seam welders as well as two CNC robotic welders with horizontal travels ranging to 29 feet. A blast machine cleans both plate and structural metal, while several plasma and laser cutters perform plate cutting. A 30-foot-long, 1,375-ton press brake handles forming operations.

To avoid subbing out work, the company ventured into CNC machining with the addition of an HMC. Today, two CNC machining centers with rotational machining heads and a three-axis vertical mill sit alongside the fabricating equipment.

“Customers don’t like to have a weldment done here, then have to move it someplace else for other operations,” Mr. Bahl says. “They want to cut one purchase order and get it complete. If you can bring machining in-house, at least you can move things around to accommodate the customer.”

With this in mind, the shop purchased the Giddings & Lewis VTC 1600 to bring even more jobs in-house. According to Mr. Bahl, Certain applications simply can’t be performed on regular machining centers.

“Sometimes you can’t get into an area to mill; you have to turn it,” he says.

Weldall looked at three different dealers in its search for a vertical turning machine. Ultimately, it chose the VTC 1600, partially because of the builder’s quick delivery time, Mr. Bahl says. While the other two dealers quoted delivery times ranging between 18 and 30 months for equipment built overseas, Giddings & Lewis was able to deliver its machine in only 4 months.

The builder attributes its ability to meet this delivery time to its modular approach to machine design and production. Interchangeable modules for components such as toolchangers, tables and pallet changers reduces the time required to build machines and increases reliability, the company says. According to Mr. Bahl, this allows Weldall to interchange parts easily and ensures that new parts are almost always available.

Service was another factor that led Weldall to choose the VTC 1600. The company needed help to become acquainted with vertical turning, and a pre-installation meeting at its facility reviewed everything involved in the installation process, from the foundation, staging areas and lift equipment to the required power and fluids. After the completing the installation, the machine tool builder sent a run-off specialist to train operators and assist with programming and processing. The builder continues to assist Weldall whenever needed.

“You can’t afford to have the machine down for weeks at a time,” Mr. Bahl says. “When we call Giddings & Lewis, they’re usually down here the same day or the next day.”

The VTC features a hydrostatic ram with high dynamic stiffness and vibration damping to enable accurate, heavy cuts, the builder says. Weldall opted for a vertical live spindle attachment and a C axis, which enables plunge milling and helical interpolation. In addition to the live spindle, a 360,000-position C-axis table provides flexibility. The head is stored in the tool magazine for easy head changes. The company also opted to purchase a right-angle head for the live spindle to perform operations on the outside of the part. Full X-axis travel left and right of center enables cutting on both sides of the center. In addition, this feature permits probing in diameters rather than radii.

One example of a new part made possible by the addition of vertical turning is a wastewater pump. Mr. Bahl says the component was impossible to machine on anything but the VTC because the shop couldn’t get a milling cutter inside the part. The operations performed on the part include turning, boring and facing. With the live spindle, Weldall can drill, tap and mill. The live spindle’s right-angle head reduces cycle time because a second setup is not required to machine the large tap on the side of the part. Additionally, the on-machine part probe allows operators to save time on both positioning and inspection.

According to the company, vertical turning capability has made a real difference in satisfying customer demand. By giving Weldall the responsibility for the welding and machining of their projects rather than using several sources, customers can benefit from uniform quality and consistent, on-time delivery.